Apparatus and method for processing municipal waste into bio-ethanol

ABSTRACT

A process and apparatus for recycling municipal domestic waste comprises subjecting the waste to steam at 150° C.-200°. After steam treatment, the resultant material is separated into constituent parts and biomass and/or plastics subjected to further treatment. The further treatment preferably produces bioethanol from the biomass and diesel from the plastics. As an alternative, some or all of the biomass may be gasified in order to produce hydrogen which may, in turn be fed to a fuel cell to produce an electrical output. The bio diesel or bioalcohol can also be used to produce electricity.

The present invention relates to the recycling of waste material andmore particularly to the recycling of municipal domestic waste.

There are a number of ways of dealing with municipal domestic waste,otherwise known as municipal solid waste, but the two most commonmethods are either by landfill or by incineration. Both these methodshave inherent problems associated with them. When utilising landfill,the waste is buried without sorting. It takes up valuable space andrenders land unusable for many years. In addition, toxic effluent canleak into the land. Further, suitable locations for landfill sites arebecoming increasingly difficult to find.

As far as incineration is concerned, this usually requires the waste tobe sorted into combustible and non-combustible waste with thenon-combustible waste being sent to a landfill site and the combustiblewaste burnt. However, the burning of waste usually creates sulphuremissions and requires high unsightly chimneys. Additionally,incinerators are not efficient because they require high energy inputs.

More recently, there have been proposals to dispose of municipal wasteby utilising an autoclave charged with the waste material to be treatedand supplied with steam from a steam accumulator. An example of this isdisclosed in U.S. Pat. No. 5,190,226 where solid waste material isprocessed at pressure of 4 bar. While these proposals are a moreenvironmentally friendly solution than the two previous common methodsdescribed above, they are inefficient as they are batch processes. Acontinuous process has been developed in e.g. U.S. Pat. No. 6,752,337but special equipment has been proposed in order to maintain a highlypressurized steam processing unit which is both expensive and hazardous.

WO-A-2008015424 discloses apparatus and methods for recycling wastematerials, but the design was energetically inefficient. WO-A-2009095693improved the initial design by injecting the steam only into the wastematerial.

The present invention seeks to provide further solutions to recyclingmunicipal domestic waste which is both energy efficient andenvironmentally friendly. The process plant is modular in design andwill take unsorted waste and thermally treat it using a continuous steamprocess. Preferably the system also addresses the problem of odourgenerated from the plant.

According to the present invention there is provided an apparatus fortreating solid waste material as defined in claims 1 and 6. Preferably,the apparatus comprises:

-   -   a first cylinder with an inlet for waste to be introduced at one        end and an outlet at the other end, wherein the first cylinder        is rotatable about an axis along the first cylinder and the        first cylinder including steam inlets for introduction of steam        into the interior of the first cylinder;    -   a heating jacket surrounding the first cylinder;    -   a second cylinder extending along said axis and rotatable        thereabout, wherein the second cylinder has an inlet at one end        for receiving material from the outlet of the first cylinder and        a second cylinder outlet at the other end. The new design is        more energy efficient than previously known designs. The second        cylinder which encases the first cylinder has heat from the        heating jacket radiating thereinto rather than being lost to the        atmosphere. This is also the case with other heat generated in        the first, inner, cylinder. The partially treated waste that is        travelling through the second cylinder thus more fully converts        into biomass and/or dries whilst in the second cylinder.

It is advantageous for the recycling process to be a continuous processthat is easier to achieve when each cylinder is elongate with the inletat one end and the outlet at the other end. The drive is arranged torotate the first, inner cylinder and in this manner transport thematerial along the vessel whilst also mixing the waste material toensure that it is fully treated.

Normally, the steam inlets are provided in steam pipes in the firstcylinder. The steam inlets may be fixed relative to the interior of thevessel. The steam inlets are arranged to inject steam at a temperatureof 160° C. to 200° C., and so provide a large amount of kinetic and heatenergy directly in to the waste material.

A microwave treating station can treat the biomass either in between thefirst cylinder and the second cylinder or at the end of the secondcylinder. The microwave treating station can be used to further enhancebiomass production. Clearly, removal of metallic wastes will beimportant before microwave treatment and it may be that this embodimentis principally used with certain specialist waste known to containminimal amounts of metallic material such as food waste.

The treated waste material preferably comprises a biomass containingcellulose material and containing less than 1% sulphur. The biomass isuseful in a large number of ways, providing key benefits of the presentsystem.

Normally, a sorting chamber is provided where the treated waste materialis separated into plastics, ferrous metals, non-ferrous metals andbiomass of cellulose material. Thereafter, the biomass is transferred toa hyperbaric engine or a fuel cell or to a conversion unit forconverting the biomass into bio-diesel, an organic alcohol, such asbio-ethanol or bio-butanol, or an aviation fuel. The bio-fuel can beused to power a generator or generators to produce electrical energy ormay be used to power other engines (e.g. aircraft engines) or othergenerators. In order that the present invention is more readilyunderstood, embodiments thereof will now be described by way of example,with reference to the accompanying drawings in which:

FIG. 1 shows a diagrammatic representation of process plant according tothe present invention;

FIG. 2 shows one end of the twin contra-rotating cylinder of the presentinvention;

FIG. 3 shows the twin contra-rotating cylinders of the presentinvention;

FIG. 4 a shows a cross section, at one end of the twin cylinder;

FIG. 4 b shows a cross-section at the other end of the twin cylinderapparatus of the present invention; and

FIG. 5 shows a representation of the downstream plant that processes thebiomass of the present invention.

Firstly, it should be noted that many of the detailed explanations ofcomponents and use are provided in WO-A-2008015424 and WO-A-2009095693and the contents of these documents are incorporated herein byreference. These documents should be consulted for ways of implementingmany of the parts of the overall plant of which the apparatus of theinvention forms a core part. The principle difference is the use of thetwo cylinder design to make the production of the biomass more efficientas more of the heat energy is used in the process to either convert thewaste into biomass or to further dry the biomass. The methods ofproducing biomass and fuels described in WO-A-2009095693 are equallyapplicable to the present invention.

Contra Rotating Waste Processing Chambers

The waste process unit comprises two contra-rotating chambers or drums.

The inner drum (or first cylinder) 10 is located on a central driveshaft, which is hollow and is connected to a drive motor 12 and chaindrive 14. The inner chamber 10 is located and connected to the driveshaft 20 by a series of “flights” 16 forming an Archimedes Screw, thisscrew 16 also supports the drum. The drive shaft 20 acts as therotational axis of the inner drum 10. The inner drum 10 is fitted with aheated jacket 18 which provides heating to the inner chamber 10 bydirectly heating the waste and the air surrounding it to a temperatureof between 160° C. and 200° C. The heating jacket 18 also heats theouter chamber 22 by radiated heat from the outer surface of the heatingjacket 18.

The heating jacket 18 is served by a high temperature fluid (thermalfluid oil at a temperature of up to 250° C.) which is introduced intothe heating jacket 18 via a two-port rotating union connected to asystem of pipe work 24 which runs down the centre of the central hollowshaft 20.

Connection from the high temperature heating medium pipes 24 and theheating jacket 18 is achieved by two pipes (flow and return) radiatingfrom the central drive shaft 20 to the jacket connections. These pipeswill be positioned along the edge of one of the flights 16 so as not tocause a restriction.

Steam at a pressure of between 6 to 9 bar will be injected in the wasteduring its travel through the inner chamber 10. This will be achieved byinjecting steam into the hollow shaft 20 and allowing it to exit througha series on small jets/perforations in the wall of the hollow shaft 20.

The external rotating chamber 22 or drum will be completely independentof the internal chamber 10 and will be provided with an external drive26.

This external drive will be via rotating wheels 28 external to therotating chamber 22 which will impart rotation about the drive shaft 20via metal tires fitted to the external surface on the external chamber22. This external chamber 22 will also be fitted with a series offlights 30 to impart motion to the waste in the opposite direction tothe first rotating chamber 10.

Untreated waste is introduced into the internal rotating chamber 10 viaa hopper at one end. Waste is introduced at the rate of approximately 10tonnes per hour which means that the chamber will remain half fullduring its cycle.

The waste is heated to between 160° C. and 200° C. and injected withsteam at between 6 to 9 bar pressure.

The waste will take approximately thirty minutes to traverse theinternal chamber 10, at the end it will fall into the second rotatingchamber 22 which is rotating in the opposite direction than the first.

The waste will take approximately thirty minutes to reach the exit bywhich time it has undergone further treatment and drying to a moisturecontent of between 20 to 30%.

At the end of the cycle (approximately one hour) the treated waste willtumble onto a conveyor to be carried to the next stage of the process.

The drive 12 for the internal chamber 10 is achieved via an electricmotor and gearbox fitted with a chain 14 and sprocket drive.

The drive for the external chamber 22 is via driven wheels 28 running ona steel tire around the perimeter of the chamber.

Drive to these wheels 28 is achieved from the same motor 12 via thegearbox and drive shaft 20.

Biomass Conversions

The biomass produced in the current process has a number of uses asoutlined above. The biomass produced in reaction chamber C (FIG. 1) hasadvantageously been sanitized and reduced in volume. Importantly, thesteam processing has disrupted the structure of the organic materials sothat the cellulose and other constituents are opened and more readilyavailable for downstream processing. The biomass is essentially a sourceof cellulose that has been treated so that the cellulose is readilyavailable for further processing, such as to form bio-fuel, bio-alcohols or the like.

Fermentation of Biomass to Fuel Alcohol

The production of alcohols by fermentation of a biomass is one of theoldest biotechnological methods. Also the use of fermentative recoveredethanol as a source of energy has been known for a long time, but hasnot been commercially used due to costs being higher in comparison tothe recovery of petroleum in the past. The possible use of bio-ethanolhas new importance as source of energy as supplies of petroleum becomemore scarce and the cost increases.

The development of renewable biofuels is an international prioritymotivated by both economic and environmental concerns, includingreduction of greenhouse gas emissions, enhancement of the domestic fuelsupply and maintenance of the rural economy. The use of microbes toproduce biofuel materials is a particularly attractive way to producethe biofuels, particularly when the microbes do so by utilising wasteproducts generated by other processes.

Gasification of Biomass

Synthesis gas (‘syngas’) was first developed as a major by-product ofthe gasification of coal and of carbonaceous materials such asagricultural crops and residues. In contrast to combustion, whichproduces primarily carbon dioxide and water, gasification is carried outunder a high fuel to oxygen ratio and produces largely hydrogen gas (H₂)and carbon monoxide (CO). Thus, syngas is composed largely of H₂ and CO,together with smaller amounts of CO₂ and other gases. Syngas can bedirectly used as a low-grade fuel or as the feed for fuel cells.Alternatively, it can be used in catalytic processes to generate a widevariety of useful chemical products, such as methane, methanol andformaldehyde. The biomass of the present invention is eminently suitableas the feed for forming syngas.

Anaerobic microorganisms such as acetogenic bacteria offer a viableroute to convert syngas to useful products, in particular to liquidbiofuels such as bio-ethanol and bio-diesel. Such bacteria catalyze theconversion of syngas with higher specificity, higher yields and lowerenergy costs than can be attained using chemical processes. Severalmicroorganisms capable of producing biofuels from waste gases and othersubstrates have been identified.

For example, three strains of acetogens have been described for use inthe production of liquid fuels from syngas: Butyribacteriummethylotrophicum (Grethlein et al., 1990; Jain et al., 1994b);Clostridium autoethanogenum (Abrini et al., 1994); Clostridiumljungdahlii (Arora et al, 1995; Barik et al., 1988; Barik et al. 1990;and Tanner et al., 1993).

Clostridium ljungdahlii and Clostridium autoethanogenum are known toconvert carbon monoxide to ethanol. US patent application No.2007/275447 describes Clostridium carboxidivorans, ATCC BAA-624, “P7”capable of synthesizing, from waste gases, products which are useful asbiofuel, in particular, P7 can convert carbon monoxide to ethanol.

Acid Hydrolysis of Biomass for Alcohol Production

This can be as described in WO-A-2009095693 but it is preferred if thefollowing technique is used.

The initial steam and heat process produces a large quantity of biomasswhich is predominately cellulosic. With a calorific value of between 15to 16 Mj/kg at the 15% moisture content when leaving the steam processrising to 17 to 18 Mj/kg when further dried. This biomass containsvirtually no sulphur and thus provides a much cleaner fuel than fossilfuels.

This basic cellulistic fibre can be treated in many ways, namelygassified to produce a “Syngas”, anaerobically digested to producemethane or used as a feed stock to produce bio-ethanol.

In all the above cases the fuels could be further processed to producean input gas (Hydrogen and/or ethanol) suitable for use in a fuel cell.This would produce a direct current electrical output for sale to thelocal electricity supplier.

However our preferred route is to process the biomass fibre into bioethanol, bio butanol, biodiesel and aviation fuel.

The biomass has been first heat treated to sanitise the material byhalting undesirable anaerobic processes and to render it amenable tohydrolysis. Which is the first stage of the bio-ethanol production.

The preferred hydrolysis method is acid hydrolysis, which can utiliseany suitable acid but in this case will usually be sulphuric acid.

The biomass is fed into the acid treatment vessel and sulphuric acid ata concentration of 70% is added. A quantity of water is added to thetreatment tank at a temperature of 90° C. until the acid concentrationhas been reduced to 12%. During this process the temperature remains at90° C. The hydrolysis process takes approximately 5 hours in total.

Acid hydrolysis is a chemical process in which acid is used to convertcellulose and hemicelluloses into sugar and lignin. The hydrolysing aciddegrades the chemical bonds of the cellulose to produce hexose andpentose sugars to a high concentration solution necessary for commercialfermentation. The insoluble lignin within the biomass remains solid.

The acid—sugar solution is separated into its acid and sugar componentsby means of ion exchange technology which separates the componentswithout diluting the sugars.

The acid component of the solution is recycled and concentrated to 70%,any acid that is left in the sugar solution is neutralised by theaddition of lime which makes hydrolysed gypsum. This gypsum can be soldas a byproduct to the building industry for the manufacture of buildingmaterials or to agriculture as a soil improver. For example: thematerial can be used to produce plaster board.

The gypsum component (CaSO4) is readily separated from the sugarsolution by filtration.

At this point the system has produced a clean stream of C6 and C5 sugarssuitable for fermentation

The sugar solution is fed into the fermentation vessels and yeast added,normally this will be saccharomyces cervisiae (brewers yeast) which willproduce a first stage ethanol of around 12% ethanol by volume. This willtake around 36 hours. Further treatment of the low grade ethanol withdistillation will concentrate the ethanol to approximately 85% with thefinal ‘polishing’ via molecular sieve to the final 98.9%.

Any residue of water and unfermented sugars from the distillationprocess are returned to the beginning of the process to recycle thewater and further conversion of the sugars to bio ethanol.

Self sustainable energy usage can be achieved by the use of the ligninto fire the process steam boilers.

The lignin, remaining a solid can be easily removed from the acid/sugarsolution by centrifuge. With the removal of moisture and drying,moisture contents of less than 5% can easily be achieved providing acalorific value of around 16 Mj/kg. This dried lignin can then be usedas a solid fuel to power the plant steam boilers.

Being in a fibrous form, the lignin fuel can be fed directly into theboiler via a fluidised bed thus eliminating the need for pelletisation.Based on the throughput of biomass, sufficient lignin can be produced tomeet the process heating load especially with the additional use ofefficient heat recovery systems at the various heating and coolingstages.

The production of electricity can also be achieved with the use of gasturbine driven generators, using some of the ethanol, to provide theelectrical requirement for the plant. This has the additional advantagethat the energy in the exhaust gasses from the gas turbine can alsocontribute to the heating requirement of the plant.

Alternative methods of electrical production can be achieved by the useof direct ethanol fuel cells, providing a three—fold contribution to theproduction plant of electricity, water and heat.

Advantages of the new acid hydrolysis process include:

-   -   methods of hydrolysis are available which would be employed to        reduce the overall size of the system, in particular would be to        combine the hydrolysis and fermentation steps is possible with        the use of an intracellular enzyme    -   The improved hydrolysis technique would reduce the overall size        of the plant by eliminating the need for the direct hydrolysis        section but would necessitate the increase in size of the        fermentation section. There would be no reduction in overall        throughput time but would have significant reduction on energy        usage for the plant.    -   With the full acid hydrolysis described above there is a        considerable energy usage in both heating and maintaining the        hydrolysis fluid at the required temperature also re        concentrating the acid solution from 12% to 70%. The parameters        are determined mainly due to the time restraints imposed. It is        therefore viewed the reduction in acid concentration to 50% and        the temperature being maintained at 60° C. would reduce the        overall energy requirement by approximately 60% and the acid        usage by approximately 50%, although the hydrolysis would be        extended from 5 to 8 hours.

This new acid hydrolysis and bio-ethanol production technique may beused with earlier apparatus and methods such as disclosed inWO-A-2008015424 and WO-A-2009095693 or in other fields where acidhydrolysis is desired and the technique is not in any way limited to theapparatus described herein.

Microwave Catalytic Biomass

Chinese patent publication CN 100999676 (Anhui Univ of Tech) describesmicrowave catalytic biomass cracking process for preparing biologicaloil with rich acetone alcohol features using sodium carbonate ascatalyst, silicon carbide as microwave absorbing medium, microwavesource as heat source for cracking biomass, and ice water mixture forcooling volatile component to obtain biological oil with rich acetonealcohol.

By means of the unique temperature effect of microwave in a biomassparticle and the unique catalyzing effect of sodium carbonate incracking biomass, the process realizes the creation of acetone alcoholin high selectivity.

Production of Butanol

The fermentative production of butanol is also well known. Internationalpatent publication WO 2008/025522 (Bayer Technology Services GmbH)relates to a method of producing bio-alcohol. In particular ethanol orbutanol, from biomass, in which the biomass is comminuted, the remainingbiomass is fed to a fermentation and the alcohol is obtained from theproduct of the fermentation, insoluble components and/or non-fermentablesugars being separated off from the biomass before the fermentationand/or yeast and bacteria are separated off after the fermentation.

The use of Biomass in Fuel Cells

The electric power industry has generally been looking toward the use offuel cells in relatively large electrical power generating applications.Power generation by fuel cells offers the advantages of high efficiencyand low environmental emissions. Thus, fuel cells may offer a moreeconomical means of power production than other existing power producingtechnologies.

Molten carbonate fuel cells and solid oxide fuel cells are well suitedfor using heated gas streams and, thus, show great promise in industrialpower generation applications. Biomass gasifiers can be used as sourcefor the feed suitable for use in these fuel cells. As described above,the gases required as fuel cell feed are readily obtainable from thegasification of the biomass of the present invention.

Greater efficiency in conventional fuel cells may be obtained throughintegration with biomass gasifiers, for example, a combined gasifier andfuel cell system wherein the gas stream travels from the gasifierthrough an external carbon dioxide separator. US patent application No.2002/194782 (Paisley) describes an integrated biomass gasification andfuel cell system wherein the electrochemical reaction in the fuel cellis effected by providing the reactant gases from a gasifier. Fuel gasfrom the gasifier is directed to the anode of the fuel cell and at leasta portion of the exhaust gas from the anode is directed to a combustor.The portion of the exhaust gas from the anode is then combusted torecover residual energy to increase the overall efficiency of integratedbiomass gasification and fuel cell system. Also, the oxidant gas fromthe combustor may be directed to the cathode of the fuel cell.

U.S. Pat. No. 5,736,026 (Energy Res Corp) entitled “Biomass-fuel cellcogeneration apparatus and method” describes the integrated ethanolmanufacturing by fermentation of biomass, with an electrical fuel cellgenerator of electrical and heat energy, the cogeneration including useby the fuel cell of the alcohol, and of the carbon dioxide from thefermentation, which increases the generation of energy, and use by thealcohol manufacturing of the heat and electrical energy from the fuelcell, which increases the fuel manufacture.

It is shown from the foregoing description, that the biomass produced bythe present invention can be used in a wide variety of ways. Normally, aparticular plant will concentrate on a particular one of thesedownstream processes, e.g. generating electricity from a fuel cell, orthe production of bio-fuels and bio-alcohols. The skilled person mayimplement this using one of the techniques described or referenced, orother techniques known in the art or as may be developed.

SUMMARY

In this document, the term ambient pressure is used to define thepressure in the vessel 30 when the vessel is not sealed to gas flow. Thepressure in the vessel will thus normally be atmospheric pressure orwhatever the prevailing pressure is around the plant. The pressurewithin the vessel may be negliably higher than the pressure around theplant due to the steam injection even without the vessel being sealed.

The term ambient temperature is used in this document to refer to thetemperature surrounding the plant which will vary due to location,season and general weather conditions. Cellulose material generallyrefers to cellulose and hemicellulose unless the context clearlyindicates differently.

Generally, this invention relates to a process and apparatus forrecycling municipal domestic waste comprises subjecting the waste tosteam at 150° C.-200° C. After steam treatment, the resultant materialis separated into constituent parts and biomass and/or plasticssubjected to further treatment. The steam treatment advantageouslysanitizes the treated material and significantly reduces the volumethereof. Importantly, the steam treatment disrupts the cellulose andother organic materials so that the fibres are open allowing the steamtreated biomass to be more easily converted to bio-fuel, bio-alcohols,etc. The further treatment preferably produces bio-ethanol from thebiomass and diesel from the plastics. As an alternative, some or all ofthe biomass may be gasified in order to produce hydrogen which may, inturn be fed to a fuel cell to produce an electrical output.

1. An apparatus for extracting bio-fuel from solid waste material, theapparatus comprising: an inner drum (10) with an inlet for wastematerial to be introduced at one end and an outlet at the other end,wherein the inner drum is rotatable about its axis; and an outer drum(22) at least partially surrounding the inner drum (10) and rotatablethereabout, wherein the outer drum (22) is adapted to receive said wastematerial from the outlet of the inner drum and is provided with anoutlet to output treated said waste material, characterised in that theapparatus comprises means (24) for introducing steam into the interiorof the inner drum (10) and is configured so that in operation theinterior of the drums is substantially at ambient pressure. 2.-30.(canceled)
 31. The apparatus of claim 1, wherein the outlet of thesecond drum (22) is located at the same end of the apparatus as theinlet of the inner drum (10) and said waste material is received fromthe inner drum towards the other end.
 32. The apparatus of claim 31wherein means (24) for introducing steam into the interior of the innerdrum comprises a hollow shaft with perforations through which steam isinjected into the interior of the inner drum.
 33. The apparatus of claim1 further comprising heating means for heating the inner drum (10), andwherein the heating means is selected from the group consisting ofheated air, a heating jacket (18), an exterior steam jacket, and aheating element.
 34. The apparatus according to claim 1, wherein theouter drum (22) rotates in the opposite direction to the inner drum. 35.The apparatus according to claim 33, wherein heating means heat, andmaintain, the interior of the inner drum (10) at a temperature of 160°C. to 180° C.
 36. The apparatus according to claim 1 wherein theinterior of the drums is at a pressure under 2 bar.
 37. The apparatusaccording to claim 1, wherein said means for introducing steam into theinner drum comprises steam inlets into the interior of the inner drum(10).
 38. The apparatus according to claim 37 wherein the steam inlets(24) are fixed relative to the interior of the inner drum (10).
 39. Theapparatus according to claim 1, wherein steam is injected into theapparatus at a temperature of 150° C. to 200° C.
 40. The apparatusaccording to claim 1, further including means for transferring saidwaste material from the inlet of the inner drum (10) to the outlet ofthe outer drum (22).
 41. The apparatus according to claim 1, wherein thetreated said waste material comprises a biomass of cellulose materialcontaining less than 1% sulphur.
 42. The apparatus according to claim 1,wherein the outlet is connected to a sorting chamber where the treatedsaid waste material is separated into plastics, ferrous metals,non-ferrous metals and biomass of cellulose material.
 43. The apparatusaccording to claim 42, wherein said biomass is transferred to ahyperbaric engine, a fuel cell, or a conversion unit for converting thebiomass into biodiesel or an organic alcohol, such as bio-ethanol orbio-butanol, or an aviation fuel.
 44. The apparatus of claim 43, whereinthe apparatus further includes electrical generators powered by thebiodiesel or organic alcohol.
 45. The apparatus of claim 1 wherein theouter drum (22), surrounds the inner drum (10) such so as to provide aradial overlap, and wherein the radial overlap is at least half of thelength of the inner drum, is at least three quarters of the length ofthe inner drum or extends over substantially all of the length of theinner drum.
 46. A method for treating waste material comprising thesteps of: a) inputting waste material into an apparatus according toclaim 1, and b) treating the waste material with steam at a temperatureof 150° C. to 200° C. in the first cylinder or inner drum.
 47. Themethod of claim 46 wherein steam is injected only in to the wastematerial.
 48. The method of claim 46 wherein the waste material isparticulate waste material or biomass.
 49. The method according to claim48, wherein the biomass is further treated to form a fuel selected from:biodiesel, fuel for a fuel cell, bio-alcohol, aviation fuel or asubstitute fossil fuel.